Speed Signal Circuit: Procedure

1. Check for a short in the circuit that is connected to the junction block connector shown in the wiring diagram.

   HINT: 

   If the voltage is not as specified, it is possible that an ECU or circuit has a malfunction. The malfunctioning ECU or circuit will be diagnosed in the following steps.

   1. Disconnect the C59 junction connector.
   2. Disconnect the C58 junction connector.
      Fig 1: Junction Connector (C58 & C59)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION
      
      

      *a	Front view of wire harness connector (to Junction Connector)

   3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection	Switch Condition	Specified Condition
      C59-5 - Body ground*1	Ignition switch ON	4.5 to 14 V
      C58-6 - Body ground*2	Ignition switch ON	4.5 to 14 V
      C58-7 - Body ground	Ignition switch ON	4.5 to 14 V

      • *1: w/ Tire Pressure Warning System
      • *2: w/ Smart Key System
      RESULT
      
      

      Result	Proceed to
      Voltage is not as specified in one circuit	A
      Voltage is as specified in all circuits	B

B → See step   11 

A: Go to next step 

1. Select the circuit for which the voltage was not as specified in the previous step.
   RESULT
   
   

   Tester Connection	System that Uses the Circuit	Proceed to
   C59-5 - Body ground	Tire pressure warning system*1	A
   C58-6 - Body ground	Smart key system*2	B
   C58-7 - Body ground	SFI system, automatic transaxle system*3	C

   • *1: w/ Tire Pressure Warning System
   • *2: w/ Smart Key System
   • *3: for Automatic Transaxle

B → See step   4 

C → See step   5 

A: Go to next step 

1. Disconnect the C59 junction connector.
2. Disconnect the C40 tire pressure warning ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C59-5 - C40-2 (SPD)	Always	Below 1 Ω
   C40-2 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   20 

1. Disconnect the C58 junction connector.
2. Disconnect the C43 power source control ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C58-6 - C43-23 (SPD)	Always	Below 1 Ω
   C43-23 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   17 

1. Check the vehicle type.
   RESULT
   
   

   Result	Proceed to
   for Manual Transaxle	A
   for Automatic Transaxle	B

B → See step   7 

A: Go to next step 

1. Disconnect the C58 junction connector.
2. Disconnect the A35 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C58-7 - A35-15 (SPD)	Always	Below 1 Ω
   A35-15 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   18 

1. Disconnect the C58 junction connector.
2. Disconnect the A32 junction connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C58-7 - A32-12	Always	Below 1 Ω
   A32-12 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Check for a short in the circuit that is connected to the junction connector shown in the wiring diagram.
   1. Disconnect the A32 junction connector.
      Fig 2: Junction Connector (A32) Connector End View

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION
      
      

      *a	Front view of wire harness connector (to Junction Connector)

   2. Measure the voltage according to the value(s) in the table below

      Standard Voltage

      Tester Connection	Switch Condition	Specified Condition
      A32-14 - Body ground	Ignition switch ON	4.5 to 14 V
      A32-13 - Body ground	Ignition switch ON	4.5 to 14 V

      RESULT
      
      

      Result	Proceed to
      NG (A32-14 - Body ground)	A
      NG (A32-13 - Body ground)	B
      OK	C

B → See step   10 

C → REPAIR OR REPLACE HARNESS OR CONNECTOR (JUNCTION CONNECTOR IS DEFECTIVE) 

A: Go to next step 

1. Disconnect the A32 junction connector.
2. Disconnect the A35 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A32-14 - A35-15 (SPD)	Always	Below 1 Ω
   A35-15 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   18 

1. Disconnect the A32 junction connector.
2. Disconnect the B31 TCM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A32-13 - B31-3 (SPD)	Always	Below 1 Ω
   B31-3 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   21 

1. Disconnect the C50 meter connector.
   Fig 3: Checking ECU Terminal Voltage (Input Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   C50-32 (+S) - Body ground	Ignition switch ON	4.5 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Combination Meter Assembly)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A36 skid control ECU connector.
   Fig 4: Checking Combination Meter Assembly (Output Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A36-11 (SP1) - Body ground	Ignition switch ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Skid Control ECU)

NG → See step   14 

OK: Go to next step 

1. Check the input waveform.
   Fig 5: Checking Combination Meter Assembly With Waveform (Speed Signal)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Reconnect the C50 meter connector.
   2. Remove the combination meter assembly with the connector(s) still connected.
   3. Connect an oscilloscope to terminal C50-31 (SI) and body ground.
   4. Turn the ignition switch to ON.
   5. Check the signal waveform according to the condition(s) in the table below.
      MEASUREMENT CONDITION
      
      

      Item	Condition
      Tester connection	C50-31 (SI) - Body ground
      Tool setting	5 V/DIV., 20 ms./DIV.
      Condition	Driving at approx. 20 km/h (12 mph)

      OK

      The waveform displayed is as shown in the illustration.

      HINT: 

      When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by A in the illustration narrows.

NG → See step   19 

OK → See step   15 

1. Disconnect the C50 meter connector.
2. Disconnect the A36 skid control ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C50-31 (SI) - A36-11 (SP1)	Always	Below 1 Ω
   A36-11 (SP1) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   16